I bought the Rokinon 24 mm F/1.4 specifically for night photography. The fast F/1.4 lens allows you to shoot astrophotography at lower ISO's and to get less noise in your images. This lens is known for its sharpness and it doesn't have much coma. Coma is the distortion of the stars at the edges of images. The other option I was considering was the Sigma 20 mm F/1.4 but that lens in known for having issues with coma and the Rokinon is much cheaper.
I haven't had time to take it out for any night photography yet, however, I did some landscape images at sunrise. In this case, all of the images were shot at f/22 and this is a manual focus lens.
I had to return the first lens for problems with the focus ring. It was frozen when I first opened the box and then it was very sloppy. The second copy seems to be very good. I've had friends that have had to return the lens many times till they received a good copy so don't give up on the lens if you don't get a good one right away.